The Credibility Spectrum

Let’s face it, there’s a lot of “climate science” out there that’s absolute rubbish.

Whichever side of the debate you’re on. Whether you believe global warming is a political hoax or that all skeptics are funded by Exxon. No matter what your opinions are, chances are that you’ve seen or read claims that you dismiss as outlandish.

Type “climate change” into Google. Within seconds you can find statements that the Earth is warming or that its temperatue is stable (or cooling since 1998!). You can find “proof” that the warming is caused by the sun, volcanoes, flaws in the temperature data, or fossil fuel burning. You can read that the Hockey Stick graph is broadly accurate, or that it was manipulated by the IPCC to agree with a predetermined conclusion.

Whatever you read about climate change, chances are that there’s another source saying the opposite thing. It’s not like we’re all climatologists who can see straight through misinformation. So how do you possibly sort out what to believe?

When people ask me this question, I invariably respond with, “Assess the credibility.”

The “climate change analysis” you read could be from a national academy of science, or from a blogger. It could be from an atmospheric physicist or a economist. It could be from a scientific journal or a political think-tank. If we calculate credibility to be “expertise + objectivity”, it’s obvious that some sources merit more weight than others.

I’ve put together a climate change credibility spectrum, inspired by Greg Craven from the Manpollo Project. This is a basic way to assess credibility and assign weight to a source. Keep in mind that this is only a guideline. The sources in the middle, especially, could be shuffled around based on the situation. The spectrum is also only used for scientific statements, such as “the Arctic is losing sea ice”. Matters of policy, such as “cap-and-trade is our best bet”, are much more a personal opinion.  

  • At the bottom of the spectrum we have the individual. This is someone with no formal education in the field of climate science. Bloggers generally fall into this category, which is why I plan to refrain from creating my own “expert analysis” of data on this blog.
  • Above that we have the professional. This is someone who is not a scientist, but is in an occupation that requires them to keep up to date with science. High school teachers are a good example, as well as politicians or CEOs.
  • Then we have the non-publishing scientist. Someone with a scientific background, but who is not currently publishing peer-reviewed literature, does not necessarily follow methods which are accepted by the scientific community. They have a good knowledge of science, but lack the “peer-reviewed” credential.
  • Above that is the publishing scientist in any area, such as medicine, physics, or chemistry. Even if they do not study climate change, they have the basic scientific background to understand it, as well as the “peer-reviewed” check on their scientific methods.
  • The publishing Earth scientist specializes in areas closer to climate science, such as geography, geology, or environmental science. They have a more in-depth knowledge of the way the biogeochemical systems of the Earth work.
  • The publishing climatologist (or atmospheric physicist/radiative physicist/any other area that’s so relevant to climatology that we can basically classify it as climatology) is the best you can get in terms of the individual professional. They understand more about climate change, and have more widely approved methods, than any other scientist.
  • Above the individuals come groups. Universities are generally quite up-to-date in their scientific knowledge, as they are training scientists-to-be, and have a large number of scientific professors behind their statements.
  • Peer-reviewed scientific articles are often written by more than one scientist, and have undergone an extensive review process. These articles minimize bias or misconceptions as much as science possibly can.
  • Finally, professional scientific organizations employ thousands of publishing scientists, have massive reputations to uphold, and often publish their own peer-reviewed journals. Their statements carry more weight than any others.

This isn’t to say that the NAS is infallible, or that the blogger is always wrong. The credibility spectrum is simply a tool used to decide how much weight to give a statement.

So go do some reading. Do some searching and reading and watching. See what individuals, professionals, groups and scientific bodies are saying about climate change. Assess their credentials. Decide who you’re going to believe.


16 thoughts on “The Credibility Spectrum

  1. This is a good credibility spectrum here. Another thing I would recommend is not to use Google for determining the credibility of facts, but instead use Google Scholar ( It guarantees that your result will be from the second most credible source, and it’s a nice way to filter out all the crap. A couple of days ago I was trying to find out if abortion causes breast cancer: I Googled it, and found people saying all sorts of things; but when I Google Scholared it, I found no scientific papers claiming that abortion may cause breast cancer.

  2. Where is RealClimate on the credibility spectrum? It’s technically a blog, but it’s run by scientists. I would think it’s a little above The Publishing Climatologist, since it is written by several climatologists.

    • That’s a great question. I would say that it falls under “publishing climatologist” because it is the word of publishing climatologists, despite being a blog (the blog form itself doesn’t matter, it’s all about who is writing the blog). The fact that it’s more than one person running it also increases its credibility.

      Once the word of a publishing climatologist is put together in the form of an article, is peer-reviewed, and is published by a journal, then it is bumped up to “peer-reviewed scientific articles”.

      Thanks, hope you’ll keep coming back, you were one of ClimateSight’s first readers :)

      • “Thanks, hope you’ll keep coming back, you were one of ClimateSight’s first readers :)”

        Definitely. This is a really great blog on climate science. You have good in-depth information on the important topics. It may not be as juicy as RealClimate, but that stuff is a lot harder to read. Your blog is actually interesting.

      • RealClimate is written by people who actually know the technicalities of climatology (they work at NASA for heaven’s sakes). You’re right, it is pretty hard to read, even with some background knowledge on the topic. It’ll be a while before I can call myself a climatologist, assuming that works out, so for now I’m spreading awareness on the topics I am qualified to speak about. See the page “Our Purpose”.

        I’m glad you like what I have to say – please spread around to people you know.

  3. Wondering where you place journalists on that scale? I place most of them on ‘Professional’ though I think some of the least-informed only count as ‘Individual’

  4. What a shameless hierarchy of credibility, where climatologists are the kings, and other scientists are peons in understanding. You’re setting up your field to be the Country Club of AGW. How’s the view from up there?

    “publishing climatologist: … They understand more about climate change, and have more widely approved methods, than any other scientist.”. .

    This is akin to me saying that rocket scientists understand more about metals than a materials engineer, more about combustion than thermodynamics experts, more about drag than aerodymanicists, more about structures than stress engineers, etc..

    Let me again make the same example with RC (“publishing climatologists”):
    “Why does the stratosphere cool when the troposphere warms?
    14/Jan/05: This post was updated in the light of my further education in radiation physics.
    25/Feb/05: Groan…and again.”

    • I absolutely did not mean to say that publishing climatologists know more than anyone else on ANY topic of science. Only climatology. Before you judge someone too harshly, make sure you’re not misunderstanding them.

      RealClimate updated their posts because they learned more about a topic which changed some of their opinions. That’s a sign of credibility. I’d much rather that they change their posts than pretend they’re always right.

      • Happy Canada Day!

        I absolutely did not mean to say that publishing climatologists know more than anyone else on ANY topic of science. Only climatology.
        Sorry for misunderstanding, however, where I was going is this: would you say that publishing climatologists know more than anyone else on the topic of anthropogenic global warming?

        “RealClimate updated their posts because they learned more about a topic which changed some of their opinions. That’s a sign of credibility.” That is not a sign of credibility. That shows lack of understanding of one of the most fundamental aspects of this theory. Even though this is just one article, I’m willing to speculate that this kind of lack of understanding of various key elements is prominent in a cross-section of the peer-reviewed climatologists (I read a lot of blogs and papers). These are the people who are responsible for the GCMs, for all the projections, what kind of confidence should that instill in public?

        Imagine that I’m a teacher who’s been teaching you that the universe is made out of 4 elements. Then a year later I would change my opinion. Would your parents consider me a credible teacher?

        Family doctor might know more about general health and medicine than a pathologist, neurologist, or cardiologist etc, but that doesn’t mean he has the necessary understanding to claim being the best authority on cancer. I realize the analogy is somewhat weak, but you get the gist.

      • I obviously don’t know as much about radiative physics or RealClimate as you do, so I won’t comment further on that issue. At least it was in informal context – a blog – and not something more significant like an article they were trying to publish.

        “Would you say that publishing climatologists know more than anyone else on the topic of anthropogenic global warming?” No. Climatology is just one of several areas of science that deal primarily with climate change (see the recent updates I made to this post to include areas such as atmospheric physics). Additionally, as every scientist specializes, there are holes in everyone’s understanding. Nobody can study everything in detail.

        That is precisely why groups and peer-reviewed articles are more credible than any individual, no matter how well trained. If “the GCMs, the projections” were created by individual scientists and never peer-reviewed, of course we shouldn’t have much confidence in them. But they are created by teams. They are examined by many. Specialists are consulted and every facet of the projection is discussed. They are actively trying to catch their mistakes. The reports and projections that matter involve many scientists, so I don’t think the public has reason to be concerned. If the knowledge on radiative physics (or any other area) is out there, you can be pretty sure that it will be taken into account.

        The IPCC reports are not written as lightly as RealClimate posts. If RC is anything like me they spend less than an hour on each post and don’t worry about grammar. :)

        Happy Canada Day – 142 years, am I correct? What area of Canada are you from?

  5. In response to your latest reply (the nesting gets awkward after few posts)

    So I think you agree with my argument, more people have significant and credible voices with regards to AGW mechanisms than just climatologists. The problem is that these peer-reviewed groups have been isolating themselves more and more into a sort of a clique of climatologists and climate modelers.

    There was an interview with Freeman Dyson:

    Dyson: “I think the difference between me and most of the experts is that I think I have a much wider view of the whole subject. I was involved in climate studies seriously about 30 years ago. That’s how I got interested. There was an outfit called the Institute for Energy Analysis at Oak Ridge. I visited Oak Ridge many times, and worked with those people, and I thought they were excellent. And the beauty of it was that it was multi-disciplinary. There were experts not just on hydrodynamics of the atmosphere, which of course is important, but also experts on vegetation, on soil, on trees, and so it was sort of half biological and half physics. And I felt that was a very good balance.

    “Thirty years ago, there was a sort of a political split between the Oak Ridge community, which included biology, and people who were doing these fluid dynamics models, which don’t include biology. They got the lion’s share of money and attention. And since then, this group of pure modeling experts has become dominant.”

  6. Hey I resent being placed at the bottom of the credibility spectrum!!! Not really though, it really is where I belong.

    Actually I really like this, I’ve been alluding to something like this for a while though it is nice to see it explicitly stated.

    I might have to quibble with your placing of RealClimate though.

  7. Err that last line the one about realclimate is a throw away line. I was going to say something but when I re-read your spectrum I realized I was wrong and your placement is probably pretty good.

    Feel free to delete that last line and this comment if you wish.

  8. I have not read all the post/comments yet, but, has anybody taken into consideration that the magnetic North pole movement may be a factor in this situation. According to the net it is now in the Artic ocean and when I went to school(1940/50s) it was in the middle of the Artic islands.

    [I’m sure the folks at NASA thought of that before I was even born. Any scientists here (eg Tamino) want to answer Red’s question? I’m guessing that the pattern of warming in the atmosphere isn’t consistent with a magnetic cause. -Kate]

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